Lecture 7.1: Pathogenesis and Virulence Flashcards

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1
Q

what makes a disease reportable?

A

highly transmissible

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2
Q

what is a self limiting pathogen?

A

only affects the person its in; does not spread to others

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3
Q

what is a transmissible pathogen?

A

can be spread between individuals

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4
Q

for what 3 reasons are diseases reported?

A
  1. containment
  2. lower transmission
  3. reduction of exposure to others
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5
Q

what is listeria/listerosis?

A

food borne infection

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6
Q

what causes listerosis?

A

L. monocytogens

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7
Q

listerosis can take the form of ____ pathogens, causing diseases such as: (5)

A
  1. septocaemia
  2. meningitis
  3. gastroenteritis
  4. encephalitis
  5. mother to fetus transmission
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8
Q

what is septocaemia?

A

blood borne infection

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9
Q

what is meningitis caused by?

A

bacteria entering the CSF

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10
Q

where does encephalitis occur?

A

in the brain

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11
Q

listerosis is a threat for mother-fetus because it is able to __, making it highly virulent

A

cross central barrier

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12
Q

listeria has mechanisms to interact with host cell during infection; what are some examples?

A

InlB, ActA LLO

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13
Q

what is InlB?

A

protein made by bacteria

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14
Q

InlB allows bacteria to be ____ (with respect to host cell)

A

internalized

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15
Q

how does InlB help bacteria get internalized?

A

binds to MET and takes over to use clathrin to promote endocytosis

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16
Q

what is MET?

A

tyrosine kinase

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17
Q

MET is normally the receptor for ____

A

hepatocyte growth factor (HGF)

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18
Q

in normal cell function, membrane __ is used to promote endocytosis

A

clathrin

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19
Q

clathrin mediated endocytosis is used to ___ and ___

A

get nutrients and recycle the membrane

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20
Q

what is listerlysin O? (LLO)

A

a pore forming toxin

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21
Q

the expression of LLO is ___ regulated so that it is produced ___

A

tightly; at the exact moment the bacteria needs it

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22
Q

listeria cannot replicate in ____ and must do so in ___

A

phagosome; host cell cytoplasm

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23
Q

LLO is active at pH ___ (pH of __) and stops at pH ___ (pH of ___)

A

6 (phagosome); 7(host cytoplasm)

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24
Q

once listeria is endocytosed, it is packaged in a ___

A

phagosome

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25
Q

in order to replicate, what must happen to the engulfed listeria?

A

it has to escape the phagosome

26
Q

activity of LLO is critical to ____ in listeria

A

replication in host

27
Q

LLO functions by

A

dissolving the phagosome that contains listeria

28
Q

can listeria survive without LLO?

A

no

29
Q

disseminating pathogens are able to

A

spread out to other areas

30
Q

dissemination results in ____ pathogenesis

A

increased

31
Q

disseminating pathogens are associated with

A

many different diseases

32
Q

dissemination is made possible by ___ protein

A

Acet A

33
Q

what is Acet A?

A

host actin (f actin) modulating protein

34
Q

how does Acet A help in dissemination?

A

hijacks host actin to provide push for intra and intercellular movement

35
Q

the listeria that travels through cell membranes of adjacent cells while aided by actin is called ___

A

listeriopod

36
Q

dissemination causes the literiopod to have a ____ membrane

A

double

37
Q

upon invasion of listeriopod into adjacent cell, ___ is activated again

A

LLO

38
Q

what causes tuberculosis?

A

mycobacterium tuberculosis

39
Q

infection rates of M TB are climbing in ___ countries

A

developing

40
Q

M TB is endemic in areas with __ and ___

A

high population and reduced health care / medicine

41
Q

the infectious dose of M TB is ____ (around ___bacteria)

A

extremely low (1-10 bacteria)

42
Q

reasons why M TB is such a threat

A
  1. drug resilient strains
  2. treatment is long and expensive
  3. many asymptic carriers
  4. co-infection can be deadly (HIV)
  5. existing vaccine is only for short term
43
Q

treatment of TB can take ___ months

A

3

44
Q

it is estimated that ____ people have TB (around ___ of the global population)

A

2 billion (1/3)

45
Q

TB is particularly deadly in a co-infection with ___

A

HIV

46
Q

what is the vaccine for TB?

A

bacillus calmate-guerin (BCG)

47
Q

what is the tubercule?

A

mass of cells involved in immune response that wall-in bacteria

48
Q

what is at the core of the tubercule?

A

macrophages

49
Q

the mass of cells that forms the tubercule is called a ___

A

granuloma

50
Q

the tubercule exists after ____ has occured

A

M TB replicates within a phagosome

51
Q

a tubercule develops ____ cells, which are dead

A

necrotic

52
Q

some of the bacteria in the tubercule surivive in a ___ form and can ___ in the presence of stress or another pathogen

A

latent; activate

53
Q

what is a benefit for the bacteria by being in a tubercule?

A

avoids active immune response

54
Q

what is a disadvantage for the host of keeping a bacteria in a tubercule?

A

can be exposed to sub-lethal conditions, gaining resistance and then later become active

55
Q

when TB replicates in a phagosome ___ and ___ are recruited

A

t cells and macrophages

56
Q

there are ___ within the M TB genome

A

pathogenicity islands

57
Q

mycobacteria are highly equipped with

A

virulence factors

58
Q

there are ___ pathogenicity islands in M TB required for its pathogenesis

A

6

59
Q

the __ strain is ___ components of the PAI and causes it to be ___ virulent

A

delta RDI BCG; missing; less

60
Q

in lowered virulence of the delta RDI BCG strain of M TB highlights

A

the importance of specific PAI for virulence of wild-type (normal) MTB